Internal pipe-cutter.



A. B. TER TROU. IINTERNAL PIPE CUTTER. APPLICATION man NOV. 16. 19h

Patented Nov. 19 18.

NW 4G 0 m MLBJEWTAQ; Wmou pipes.

near 3. warrior, or runnna'ron, cnLironivrn.

INTERNAL PIPE-CUTTER.

. ded

Specification of Letters Patent.

Patented Nov. a, rare.

Application filed November 16, 1917. Serial 110.202371.

' To all whom it may concern:

This invention relates to an internal pipe.

cutter and particularly pertains to a cutter for use in connection with deep well drill The principal object of this invention is to provide a cutter which may be lowered into a well casing or drill pipe and thereafter operated to cut the pipe, even though the pipe is upset and does not have tool joints.

Another object of this invention is to provide a cutter for the above specified purpose which will positively engage the pipe andallow it to be drawn from the well shaft by the cutting rig.

It is a further object of this invention to provide a pipe cutter which is comparatively simple in its construction, may be readily.

and positively operated, and is so designed as to allow the operator to be constantly 1nformed as to the performance of the cutter at the remote point in the well shaft.

Other objects will appear hereinafter. The invention is illustrated, by way of example, in the accompanying drawings in which:

Figure 1 is a fragmentary view illustrating the cutter head of the tool with which the present invention is concerned.

Fig. 2 is a view through they cutter head on the line 2-2 of Fig; 1 disclosing the details of its construction and further illustrating in dotted lines the action of the mechanism.

Fig. 3 is a view in transverse section through the cutter head on the line 3'3 of Fig. 2 illustrating'the valve member provided therefor.

Fig. 4 is a view in transverse section through the cutter head on the line 44. of Fig. 2 disclosin the arrangement of the cutter blades and t eir movement.

Fig. 5 is a'view illustrating in a diagrammatical manner the operating mechanism of the cutter.

Referring more particularly to the drawrings, indicates a drill pipe which has been set in a well-shaft,and which is to be cut by a cutter head 11 with which the present invention is particularly concerned. This head is provided with a connection 12 by which it is fastened to tubular cutter stem 13. The stem 13 extends through suitable bearings at the top of the well shaft and may be rotated by power driven gearing 14. .A swivel head coupling 15 is fastened on the upper end of the stem and is connected by a flexible conduit 16 to a. fluid pressure pump 17. The stem 13 may be raised and lowered by a cable 18 or other means incorporated within the well rig.

Referring particularly to Figs. 1 and 2 it Wlll be seen that the cutter head comprises a' cyhndrical tubular body portion 19, into which the coupling'12 extends, and a co-' noidal end-portion 2O detachably secured at the lower end of the body 19. This end portion or nose hollow to receive a helical expansion spring 21 which acts against a plunger plate 22 above which an inverted frusto-conical expanding plunger 23 is mounted. These ,two plungers are connected by a centrally disposed bolt 24 and may bereciprocated along the bore of the body portion 19 and down into the cylindrical cavity of the nose. This bolt also secures a packing disk 25 in position upon the upper end of the expanding plunger 23, thus insuring that liquid under pressure within the stem 13 will force the plungers downwardly in an efi'ective manner.

The expanding plunger is provided to impart radial movement to a set of pipe-cutters 26, 27, 28 and 29, particularly shown in Fig. 4:. These cutters are formed of flat pieces of tool steel and have their inner ends T-shaped to fit within T-slots 3033, re-

spectively. These slots are disposed at right angles to each other and extend longitudinally of the expanding plunger 23, thus causing the cutters to be drawn in and out as this plunger is moved up and down. Normally the cutters are held in their innermost and'inoperative positions. The outer ends of the cutters extend through slots 34 in thewall of the body portion 19. The cutters are thus rigidly mounted for slidable movement and may be forced outwardly against the inner face of the pipe 10. The

cutting ends of thecutters are backed off in cutter head from becoming choked the chips it produces.

A slide-valve 36 is secured to the upper end of the expanding plunger and is adapted to bear against the inner surface of the side wall of the portion 19. This valve member is formed with a small opening 37 normally 1 in'register with an opening 38 of substantially twice thediameter of the small opening, thus allowing the water or other liquid within the well-shaft to flow into the cutter stem as the cutter is loweredand it is dis placed. The valve member extends up the side of the wall and is of a desired length to maintain the opening 38 closed until the ex- A panding plunger has reached the bottom of its stroke, after which it will be entirely opened and the liquid within the cutter, stem allowed to pass out through the opening and circulate around the cutter head. A circulating opening 39 is formed through the wall of the nose for a purpose which will be evident.

In order that the cutter blades may be positively held ,in their outermost cutting and operating position after the pipe has been cut, a spring catch'finger 40 is fixed to the lower face of the plunger plate 22 and will engage an opening ll in the side of the nose 20 when the plunger has reached thelower end of its stroke. It will be understood, however, that when desired this catch may be eliminated from the design without departing from the spirit of the invention.

In operation, the cutter head 11 is lowered into the pipe 10 by the cutting stem 13, to which it is rigidly fastened. When the proper depth has been reached the driving gears 14 are fastened around the stem 13 and its driving shaft torotate the cutter head in the direction of the arrow a as indicated in Fig. 4. Pressure is applied to the liquid within the stem 13 by the pump 17 and the plunger 23 forced downwardly. This movement will cause the'cutter blades to move outwardly as their inner ends travel along the upwardly extending and outwardly inclined T-slots of the expanding plunger 23. As soon as the valve member 36 has moved downwardly a short distance with the plunger, it will completely close the openlng 38 and will hold it closed until the cutter blades have moved out the extreme length of'thcir stroke; after which the opening 38 will be entirely uncovered. This condition may be readily noted by the operator as the pressure in hispump line will be instantly lowered, thus indicating, that the cutting operation has been completed. When the head is fitted with the catch 40, the plunger will be temporarily locked in its lowermost position to hold the blades out in their outermost cutting and operating positions and allow the pipe to be drawn from the well shaft by the blades.

It will thus be seen that the cutting mechanism here disclosed is simple in its construction, may be readily operated in a convenient manner, andwill act effectively to produce the result desired without great danger of breakage or wear. I

While I have shown the preferred construction of my internal pipe cutter as now known to me, it will be understood that various changes in the combination, construction and arrangement of parts maybe made by those skilled in the art without departing from the spirit of my invention as claimed.

I claim 1. An internal pipe cutter comprising a rigid tubular stem, a cutter head disposed at the lower end thereof, radially moving cutter blades mounted within said head and adapted to extend therefrom, means for retating the cutter head, fluid-pressure-operated means for forcing the blades outwardly during said rotation, meansfor locking the I blades in their outermost cutting and operating position at the completion of the cutting operation, and means for indicating to the operator that the cutting operation has been completed.

2. An internal pipe cutter comprising a rigid tubular stem, a cutter head fixed to the lower end thereof, a plunger reciprocating within said cutter head, radially moving outter blades, means whereby downward movement of the plunger will cause outward movement of the cutter blades, means for normally holding the cutter blades in their innermost and inoperative position, fluidpressure-operated means for moving said plunger, and a valve member adapted to per mit the flow of liquid from a well shaft into the cutter stem and thereafter to seal the stem during the cutting operation.

3. An internal pipe cutter comprising a rigid tubular stem, a cutter head fixed to the lower end thereof, a plunger reciprocating within said cutter head, radially moving cutter blades, means whereby downward move ment of the plunger will cause outward movement of the cutter blades, means for 1,288,969 V p a normally holding the cutter; blades in their 'erating to release the flow of liquid at the innermost and inoperative position, fluidcompletion of'the cutting operation and pressure-operated 'means for moving said thereby cause the completion of thecutting -10 plunger, a valve member adapted to permit operatlon to be indicated to the operator.

5 the flow of liquid from a; Well shaft into the In testimony .whereof I have signed my cutter stem-and thereafter to seal the stem name to this specification.

during the cutting operation, said valve op- B. TERTROU. 

